Commercial riding lawn mowers of the type used on golf courses, athletic fields and the like, are relatively large machines which often utilize cutting reels as opposed to rotary blades. Typically on such mowers two or three cutting reels are provided across the front of the mower. Additionally, one or more cutting reels are positioned in trailing relationship behind the gaps between the front cutting reels. The cutting reels make direct contact with the grass when cutting, following the contour and undulations of the terrain as the mower moves over the ground. The Toro Company, which is the assignee hereof, manufactures and sells several examples of such mowers.
Although the present invention relates to turf maintenance vehicles usable in a large variety of situations (including but not limited to cutting grass in parks, athletic fields, golf courses, etc.), the maintenance of golf courses will be utilized herein for the purposes of illustration. Continuing with the golf course example, it will be immediately appreciated that cutting grass on a golf course is a recurring and time consuming task. Further, the particular tee or fairway is typically taken out of service while the cutting is occurring. Accordingly, it is desirable to drive the mower as fast as possible while maintaining the desired cutting height and quality of cut, since the ground speed of the mower while cutting is directly related to the time necessary to cut the particular tee or fairway. However, in such settings the potential ground speed depends upon the ability of the cutting reels to maintain the desired quality of cut. Those skilled in the art will appreciate that the potential ground speed is also affected by variations in the terrain, the experience of the operator, and the turf conditions. Still other considerations include the type of grass, the moisture on the grass and/or the moisture content of the grass, and the desired cutting height of the grass.
In order to optimize the quality of cut while maximizing the ground speed, an electronic controller unit is utilized by the Toro Company of Minneapolis, Minn. on its model designation Reelmaster 5100-D. The operation of such controller is disclosed in detail in U.S. patent application Ser. No. 07/816,816, filed Jan. 3, 1992, and titled ELECTRONIC CONTROL FOR TURF MAINTENANCE VEHICLE which is hereby incorporated herein by reference.
Those skilled in the art will recognize that such controllers on turf maintenance vehicles in the past have not been utilized due to various factors, including the environment in which the machines must operate, the durability of electronic controllers, the level of applications for electronic controllers, and the expertise in the field (which was directed to mechanical solutions), among others. Additionally, diagnostic devices to determine electrical problems and malfunctions in the turf maintenance vehicle art have not heretofore been fully developed for many of the same reasons.
Since golf courses must be maintained at a high level in order to attract golfers, turf maintenance vehicles must be reliable and cannot incur more than a minimal amount of downtime. Thus, as the sophistication of the electronic controller devices increases, so too must the sophistication of the diagnostic devices which can troubleshoot electrical problems. However, the diagnostic devices must be convenient for use in the field since turf maintenance vehicles are typically repaired on site in order to further reduce downtime. Similarly, the grounds crew is oftentimes the repair personnel and so the diagnostic device must be extremely user friendly to specifically point out the source of the problem.
In the automotive art, various electronic controllers have been utilized for engine operation. The present inventors believe that such automotive controllers include error codes which are generated by the controller in the event that one or more parameters are not within expected ranges. However, the generation of an error code tends to presuppose that all errors have been predetermined. If a large number of possible errors exist, then the overhead required to determine and store all possible errors becomes very large. It also presupposes that all possible errors are known. The alternative is to generate a general error code for one or more possible errors. In the latter case, however, merely knowing that an error occurred requires that the engine is restarted and connected to a real time diagnostic device to determine the cause of the generated code. In other words, the general error code itself does not contain enough information to determine the specific cause of the problem which originally caused the code to be generated.
These problems make the automotive solution inapplicable to a turf maintenance vehicle setting. First, as alluded to above, removal of the turf maintenance vehicle to a shop for such analysis is impractical and is at odds with the original reasons to include the controller (i.e., optimize quality and speed of cutting, and minimizing downtime). Second, generation of an error code for each possible monitored parameter/fault combination is virtually impossible (i.e., due to the number of monitored parameters and calculated outputs of the 5100-D, the number of combinations is theoretically 2.sup.18 =262,144). Third, given the parameters which are monitored, often it is impossible to determine whether the condition of the parameter constitutes an error. Thus, all errors are not necessarily determined in advance, and the presupposition that all of the errors have been predetermined makes a complete list of error codes inappropriate.
Accordingly, there arises a need for a turf maintenance vehicle controller which preferably includes a memory array means to store the status of the various monitored parameters, the ability to provide such data in real time to a diagnostic apparatus, and to store the data for later analysis by either the diagnostic apparatus or a remote microprocessor.